Anthropogenic climate change due to, among other causes, unhindered CO 2 emissions is a major concern worldwide. The postcombustion capture (PCC) process using a solvent, known as chemical absorption, is currently the most effective way to reduce CO 2 emissions from large point sources. However, high capital investment costs when using the conventional packed bed absorber/desorber technology and high energy requirements during solvent regeneration are the primary obstacles for its large-scale implementation. Different process intensification (PI) technologies to desorb CO 2 from the solvent have been introduced to mitigate the energy consumption compared to the conventional packed bed technology. This work reviews different technologies for intensification of CO 2 desorption. In this context, rotating packed beds, microreactors, and membrane contactors have been explored as potential alternatives to intensify the desorption because of their superior mass and heat transfer. Alternative energy sources like ultrasound and microwaves have also been used to improve the desorption performance of conventional equipments. PI can also be realized by using novel solvents with improved desorption kinetics in combination with intensification equipment. Thus in this review, a comprehensive assessment of different existing PI technologies based on regeneration energies and regeneration efficiencies relative to conventional technology is presented. The intensification of mass transfer for the different technologies is compared, and a new parameter, named the regeneration factor, is proposed to evaluate the performance of PI equipment. This study outlines the advances in process intensification of CO 2 desorption technologies to date and presents an overview of the merits and limits of all technologies.

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A mixing cell network (MCN) was developed for the commercial diesel hydrodesulphurization process (DHDS) in a trickle bed reactor (TBR). The two-phase model is developed to simulate the performance of an industrial DHDS unit. Major hydrotreating reactions such as hydrodesulphurization (HDS), hydrodearomatization (HDA), and olefin saturation were accounted for in the developed model. The MCN model predictions on axial concentration profiles of sulphur, polynuclear aromatics (PNAs), monoaromatics (MAs), and temperature were found to be in agreement with the real-time plant data. Further, the predicted results were also compared with the plug flow model to confirm model adequacy. The results obtained in this paper show the efficacy of the MCN model in simulating multiple reactions happening in real industrial scenarios.

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